21целых4/15+1целая5/6-9целых7/30+16целых7/24=

21 4/15 +1 5/6 - 9 7/30 +16 7/24=30 19/1201. 21 4/15+1 5/6 =23 1/102. 23 1/10- 9 7/30=13 13/153. 13 13/15 +16 7/24=30 19/120